Binary search in C

binary_search.c

#include<stdio.h>
#include<stdlib.h>

int main(){
  int n, a[100], search;
 printf("Enter size of array\n");
 scanf("%d",&n);
 printf("enter %d elements\n",n);
 for(int i=0;i<n;i++){
   scanf("%d",&a[i]);
 }
 printf("Enter search element:\n");
 scanf("%d",&search);

int first=0, last=n-1, mid=(first+last)/2;

while(first <= last){
  if(a[mid] == search){
    printf("Element found at position %d!!\n",mid+1);
    break;
  }
  else if(a[mid] < search){
    first = mid+1;
  }
  else{
    last = mid-1;
  }
  mid = (first+last)/2;
}
if(first>last){
  printf("Not found!!\n");
}


  return 0;
}